Earlier this week, Panama City Beach, Florida was overwhelmed with a sweeping wave of fog that was not unlike a cloud tsunami. It creeped onto the beach and rolled right over buildings, giving off an almost supernatural aura.

Cool air offshore was very nearly at the saturation point, with a temperature near 20ºC and a dew point of about 19.5ºC. The air at this temperature can only hold a certain amount of water vapor, and how much it can hold depends heavily on the temperature. If you add more water into the air, a cloud will form, but you can also get a cloud to form by cooling the air. Drop the temperature, and it can no long hold as much water vapor, so some of it will condense out and a cloud will form.

The pictures were taken by Helicopter pilot Mike Schaeffer and JR Hott of Panhandle Helicopter. It seriously looks like ghosts sweeping over Florida. Or dementors looking for Harry Potter. Or a gigantic spiderweb covering the beach. Either way, it's so spectacular it gives me the heebie jeebies. [Panhandle Helicopter via MSNBC]